about Google Sandbox

1) Will "sandbox" happen to all websites after a while?
2) How long will the website be "sandboxed"?
3) Is there a way to un "sandbox" the website?
4) What will be your strategy if suddenly a website you are doing SEO becomes "sandboxed"

Arguably yes to some extent, although the effect is not easily measurable or obvious for all sites.

2) How long will the website be "sandboxed"?

This depends on many factors and is not a standard amount of time. 3 Months is typical but it can be less or more. It is also muddied by lots of other time and authority based factors clouding what is really going on.

3) Is there a way to un "sandbox" the website?

No

4) What will be your strategy if suddenly a website you are doing SEO becomes "sandboxed"